From 63c2f782e8f6aafbc11b14b2cb291b3dc9fc217d Mon Sep 17 00:00:00 2001
From: "Robert P. J. Day" <rpjday@mindspring.com>
Date: Tue, 30 Jan 2007 06:06:00 -0500
Subject: [POWERPC] Add "is_power_of_2" checking to log2.h.

Add the inline function "is_power_of_2()" to log2.h, where the value
zero is *not* considered to be a power of two.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 include/linux/log2.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

(limited to 'include/linux/log2.h')

diff --git a/include/linux/log2.h b/include/linux/log2.h
index d02e1a547a7e..99922bedfcc9 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -43,6 +43,17 @@ int __ilog2_u64(u64 n)
 }
 #endif
 
+/*
+ *  Determine whether some value is a power of two, where zero is
+ * *not* considered a power of two.
+ */
+
+static inline __attribute__((const))
+bool is_power_of_2(unsigned long n)
+{
+	return (n != 0 && ((n & (n - 1)) == 0));
+}
+
 /*
  * round up to nearest power of two
  */
-- 
cgit